Conical bearings

ABSTRACT

A bearing including pivoted pads having flat surfaces running on a thrust face of conical form convex with respect to the flat running surfaces of the pads.

United States Patent [191 Davis Feb.4, 1975 I CONICAL BEARINGS [75] Inventor: Anthony Roger Davis, Cirencester,

England [30] Foreign Application Priority Data Aug. 26, 1972 Great Britain 39868/72 [52] U.S. Cl 308/160, 91/488, 308/73 [51] Int. Cl.... F16c 17/06, F16c 17/08, Fl6c 23/04 [58] Field of Search 308/73, 160; 91/488 [56] References Cited UNITED STATES PATENTS 2,137,487 11/1938 Hall ..308/73 FOREIGN PATENTS OR APPLICATIONS 549,301 4/1932 Germany 308/73 OTHER PUBLICATIONS Pivoted Thrust Bearings Published in Product Engineering, April 16, 1962, pages 124 thru 132, relied upon.

Primary Examiner-M. Henson Wood, Jr. Assistant Examiner-Howard Beltran Attorney, Agent, or Firm-Thomas C. Wettach; Arland T Stein [57] ABSTRACT A bearing including pivoted pads having flat surfaces running on a thrust face of conical form convex with respect to the flat running surfaces of the pads.

1 Claim, 3 Drawing Figures PATEHTEDFEB 41915 3,863897 FIG. 7.

1 CONICAL BEARINGS This invention relates to bearings and is in particular concerned with the bearing that is formed by the slipper pads and the surface on which they run of an axial piston swash plate pump or motor.

According to the present invention there is provided a bearing that includes pivoted pads and a thrust face on which the pads run in operation, the surface of each pad that runs on the thrust face being substantially flat and the thrust face being of conical form generated from a centre about which the motion of each pad is substantially circular and so as to be convex with respect to the substantially flat running surfaces of the pads.

In a particular construction the pads are the slipper pads of an axial piston swash plate pump or motor and the thrust face is the face of the swash plate on which these slipper pads run.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawing, in which:

FIG. 1 diagrammatically illustrates a slipper pad running on a swash plate,

FIG. 2 is a diagrammatic cross-sectional view taken on the line IIII of FIG. 1, and

FIG. 3 is a diagrammatic partly sectional view taken in the direction of arrow III of FIG. 2.

The slipper pad 1 of the Figures is one of the slipper pads of an axial piston pump or motor having slipper pads freely connected to pumping pistons and reacting against an inclined swash plate thereby giving the pistons, which are located in a rotating barrel, a reciprocating pumping action due to the barrel rotation. The thrust face of the swash plate is referenced 2 in the Figures. The running surface 1A of the slipper pad 1 is substantially flat and the thrust face 2 is frusto-conical so as to be convex with respect to the pad running face 1A, the face 2 being generated from a centre about which the motion of the slipper pad 1 is substantially circular. The resultant contact between the pad and the thrust face is a line nominally along a diameter or chord of the slipper pad. In the direction of motion M of the slipper pad, i.e., peripherally, leading and trailing wedges are formed due to the conically surfaced swash plate, the larger ends of these wedges being on the leading and trailing edges of a slipper pad. The use of a surface which has an included angle of from to l79.8 and preferably of the order of 178 gives a wedge shape that is of use in generating hydrodynamic pressure due to the motion of the slipper pad. When high pressure is acting on the piston to which the pad is connected it is desirable that the slipper pad and swash-plate surfaces are separated by a thin film of oil and in the present construction hydrodynamic lubrication occurs due to the natural formation of an oil wedge in the direction of motion of the slipper pad.

The constructional principle just set forth can be utilised in other forms of thrust bearing having pivoted pads running against a thrust face.

I claim:

I. A bearing that includes an axial piston swash plate having pivoted slipper pads, and a swash plate having a thrust face on the pads run in operation, the surface of each pad that runs on the thrust face being substantially flat and the thrust face being of conical form generated from a centre about which the motion of each pad is substantially circular and so as to be convex with respect to the substantially flat running surfaces of the pads.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,863,997 Dated February 4, 1975 Inventor(s) Anthony Roger Davies It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 2, Claim 1, line 29, after "on" insert which Signed and sealed this 15th day of April 1975.

/ .v cfimalmj attest:

r T I, Y Y r r v C IL-LRQZTALL DAT-i2 RUTH C. fir-1301" Commissioner of Patents Attesting Ufficer and Trademarks FORM po'wso (0459) USCOMM-DC 603764 69 u.s. covnmazm rnm'nue orrlcs: 93 o 

1. A bearing that includes an axial piston swash plate having pivoted slipper pads, and a swash plate having a thrust face on the pads run in oPeration, the surface of each pad that runs on the thrust face being substantially flat and the thrust face being of conical form generated from a centre about which the motion of each pad is substantially circular and so as to be convex with respect to the substantially flat running surfaces of the pads. 